Date of Award
2024
Degree Type
Dissertation
Degree Name
Doctor of Philosophy in Marine Affairs
Department
Marine Affairs
First Advisor
Tracey Dalton
Abstract
Pelagic Sargassum species, long considered a vital component of Caribbean ecosystems, began to arrive on and near shore in unprecedented quantities starting in 2011; these arrivals have transformed many Caribbean people’s perspectives of these macroalgae from a native benefit to an alien invader, and are now regarded widely as a harmful algal bloom (HAB). HABs often receive attention for the ecological and economic damage they present, but other human dimensions are less commonly considered, and this is doubly true of Sargassum events. This dissertation was intended to fill increasingly pronounced research gaps by providing exploratory evidence that can be useful to managers and other decision makers as this new type of HAB exerts pressure on a region already burdened with a surfeit of economic, ecological, and social justice issues. Using mainly quantitative methods, data were collected for this tripartite study via an online survey and through fieldwork in sixteen distinct Caribbean coastal communities. This series of manuscripts describe ways in which Sargassum events impact human lives and livelihoods in the Caribbean. The first manuscript describes a panoply of perspectives on Sargassum event arrivals, impacts, and management. The second and third manuscripts are the result of surveys and interviews conducted in communities where people live and work with Sargassum of varying levels of severity. These chapters offer enhanced perspective on Sargassum’s influence on community and individual life through discourse with local people, observation of community life, and evaluation on local and regional governance of the issue.
Manuscript 1 explores how community members across the Greater Caribbean perceive Sargassum events and event management, using a broadly distributed online survey in three languages. 633 people responded to questions about a) spatial and temporal distribution of near and onshore events in and around their respective areas of concern, b) how this type of HAB affected personal and community life and the types of concerns Sargassum evoked, c) the degree to which it is a problem in the minds of locals, d) respondents’ confidence in governance and management of sever events, and e) their attitudes about Sargassum knowledge and information availability. Results indicated that Sargassum events were more broadly distributed than many sources indicated that a majority of respondents believed Sargassum to be a disaster with far reaching personal and community impacts, that dissatisfaction with government response was marked, and that ocean users, community members, and others are desirous to learn more about this phenomenon. These data are intended to provide actionable evidence for managers and community members in place of the limited news and social media anecdotes that to date have been the primary source of information about social aspects of Sargassum in the Caribbean.
Manuscript 2 examines how Sargassum events influence the wellbeing of community members in the northern Caribbean. Data were collected via fieldwork conducted in sixteen communities exposed to various levels of Sargassum incidence and abundance across four jurisdictions: Puerto Rico, the USVI, Quintana Roo (Mexico), and the Florida Keys. During the period between June 2022 and June 2023, over 580 (x̄ = 36.4 per site) intercept surveys were conducted in Spanish and English. Respondents were asked to evaluate their own wellbeing via Cantril’s ladder, in addition to questions about attitudes regarding their work lives, sense of place, community, and the extent to which they thought Sargassum and its management affected different aspects of their lives and communities. Results indicated that wellbeing was positively associated with perceived Sargassum severity, a decreased ability to catch fish, and a decreased ability to enjoy the coast; conversely, people who believed any kind or level of Sargassum management was being practiced locally had higher levels of wellbeing than people who believed that Sargassum was not managed at all. Additionally, people who believed their community was more socially cohesive had higher wellbeing scores. A follow-up analysis found that confidence in the way that Sargassum was managed as well as trust in government were significant contributors to social cohesion, demonstrating that Sargassum has primary and secondary influences on subjective wellbeing.
Manuscript 3 evaluates the application of the Intergovernmental Panel on Climate Change’s (IPCC) vulnerability assessment framework to the issue of Sargassum events, as presented in its 5th Assessment Report. Beginning in 2001, the IPCC issued a series of reports recommending a certain approach to assessing overall system vulnerability to climate change-related hazards. In 2012, a revised framework was proposed emphasizing a shift of foci from vulnerability to risk; however, for researchers who maintain an interest in vulnerability, the “new paradigm” has not been well-adopted, with most researchers choosing to retain the older framework. In this study, the new framework is applied to vulnerability to Sargassum events, using data collected in the field at the community level. During the period between June 2022 and June 2023, over 580 intercept surveys and 82 key informant interviews (x̄ = 36.4 and x̄ = 5.1 per community, respectively) were conducted in Spanish and English. Observations on the efficacy, practicality, and limitations of the new IPCC framework are presented. Finally, the appendices appended include the instruments developed to conduct the online survey (appendix A) for Manuscript 1, along with supplementary statistical tests (Appendix B), and the survey and interview instruments developed to conduct fieldwork for Manuscripts 2 and 3 (Appendices C and D). Appendix E describes adaptive capacity and sensitivity variables used to calculate vulnerability and includes summary statistics for each item. Appendix F includes values used to inform the heat map illustration in Manuscript 3.
Findings from this dissertation will be useful for decision makers invested in how Sargassum events and other HABs influence individual and community life, particularly for people interested in making more informed decisions about best management practices, people and sectors best served, and actions that can be taken with regard to mitigating these types of hazards.
Recommended Citation
Hamel, Kenneth, "SOCIETAL IMPACTS OF HARMFUL MACROALGAL BLOOMS ON CARIBBEAN COMMUNITIES" (2024). Open Access Dissertations. Paper 1686.
https://digitalcommons.uri.edu/oa_diss/1686